Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Accumulated Other Comprehensive Income [Line Items]
Beginning Balance			$ (94,652)
Other comprehensive income before reclassifications			100,507
Tax effect			(540)
Other comprehensive income before reclassifications, net of tax			99,967
Amounts reclassified out of AOCI			6,918
Tax effect of reclassification			(2,075)
Amounts reclassified out of AOCI, net of tax			4,843
Other comprehensive income (loss)	$ 29,661	$ 10,826	104,810	$ 25,745
Ending Balance	10,158		10,158
Unrealized Gain (Loss) on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income [Line Items]
Beginning Balance			1,110
Other comprehensive income before reclassifications			1,542
Tax effect			(540)
Other comprehensive income before reclassifications, net of tax			1,002
Amounts reclassified out of AOCI			0
Tax effect of reclassification			0
Amounts reclassified out of AOCI, net of tax			0
Other comprehensive income (loss)			1,002
Ending Balance	2,112		2,112
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income [Line Items]
Beginning Balance			(31,266)
Other comprehensive income before reclassifications			98,965
Tax effect			0
Other comprehensive income before reclassifications, net of tax			98,965
Amounts reclassified out of AOCI			0
Tax effect of reclassification			0
Amounts reclassified out of AOCI, net of tax			0
Other comprehensive income (loss)			98,965
Ending Balance	67,699		67,699
Pension and Other Post-Retirement Actuarial Items [Member]
Accumulated Other Comprehensive Income [Line Items]
Beginning Balance			(64,496)
Other comprehensive income before reclassifications			0
Tax effect			0
Other comprehensive income before reclassifications, net of tax			0
Amounts reclassified out of AOCI			6,918
Tax effect of reclassification			(2,075)
Amounts reclassified out of AOCI, net of tax			4,843
Other comprehensive income (loss)			4,843
Ending Balance	$ (59,653)		$ (59,653)